+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Expression of ornithine-urea cycle enzymes in early life stages of air-breathing walking catfish Clarias batrachus and induction of ureogenesis under hyper-ammonia stress

, : Expression of ornithine-urea cycle enzymes in early life stages of air-breathing walking catfish Clarias batrachus and induction of ureogenesis under hyper-ammonia stress. Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology 143(1): 44-53

The air-breathing walking catfish Clarias batrachus is a potential ureogenic teleost with having a full complement of ornithine-urea cycle (OUC) enzymes expressed in various tissues. The present study was aimed at determining the pattern of nitrogenous waste excretion in the form of ammonia-N and urea-N along with the changes of tissue ammonia and urea levels, and the expression of OUC enzymes and glutamine synthetase (GSase) in early life stages of this teleost, and further, to study the possible induction of ureogenesis in 15-day old fry under hyper-ammonia stress. The ammonia and urea excretion was visible within 12 It post-fertilization (hpf), which increased several-fold until the yolk was completely absorbed by the embryo. Although all the early developing stages were primarily ammoniotelic, they also excreted significant amount of nitrogen (N) in the form of urea-N (about 35-40% of total N). Tissue levels of ammonia and urea also increased along with subsequent developmental stages at least until the yolk absorption stage. All the OUC enzymes and GSase were expressed within 4-12 hpf showing an increasing trend of activity for all the enzymes until 350 hpf. There was a significant increase of activity of GSase, carbamyl phosphate synthetase III (CPSase III) and argininosuccinate lyase enzymes (ASL), accompanied with significant increase of enzyme protein concentration of at least two enzymes (GSase and CPSase III) in the 15-day old fry following exposure to 10 mM NH4Cl as compared to respective controls kept in water over a period of 72 h. Thus, it appears that the OUC enzymes are expressed in early life stages of walking catfish like other teleosts, but at relatively high levels and remain expressed all through the life stages with a potential of stimulation of ureogenesis throughout the life cycle as a sort of physiological adaptation to survive and breed successfully under hyper-ammonia and various other environmental-related stresses.


PMID: 16271487

DOI: 10.1016/j.cbpb.2005.09.014

Other references

Stona, A-Claire.; Berrang, C.; Santerre, H.; Georges, N.; Chimenti, R.; Kneip, Ré.; Fond-Harmant, L., 2016: Homelessness and stakeholders' involvement in the Grand Duchy of Luxembourg: a qualitative study. In 2013, between 150 and 200 people per night in the Grand Duchy of Luxembourg are estimated roofless. Abilities to respond to emergencies in the GDL are perceptibly decreased due to longer stays in emergency shelters. This study aimed to analyse...

Umeda, K.; Heike, T.; Yoshimoto, M.; Shinoda, G.; Shiota, M.; Suemori, H.; Luo, H.Yuan.; Chui, D.H.K.; Torii, R.; Shibuya, M.; Nakatsuji, N.; Nakahata, T., 2006: Identification and characterization of hemoangiogenic progenitors during cynomolgus monkey embryonic stem cell differentiation. We identified intermediate-stage progenitor cells that have the potential to differentiate into hematopoietic and endothelial lineages from nonhuman primate embryonic stem (ES) cells. Sequential fluorescence-activated cell sorting and immunostaini...

Koerber, R., 1950: Study of phagedenic ulcers in French Occidental Africa. Maroc Medical 29(297): 224-228

Pavsic Jernej; Mikuz Vasja, 1996: The Baleen whale (Balaenoptera acutorstrata cuvierii) from Miocene beds near Benedikt in Slovenske gorice, Slovenia. Razprave - Slovenska Akademija Znanosti in Umetnosti Razred za Naravoslovne Vede = Dissertationes - Academia Scientiarum et Artium Slovenica

Rossi, J., 1988: Concepts and current trends in hand splinting. The development of hand splinting within the practice of occupational therapy, rationale for appropriate splinting and recent trends in splint selection are reviewed. The therapist treating hand involved patients are employed in a variety of setti...

Mortell, K.H.; Gingras, M.; Kiessling, L.L., 1994: Synthesis of cell agglutination inhibitors by aqueous ring-opening metathesis polymerization. Journal of the American Chemical Society 116(26): 12053-12054

Squires, R.L.; Ellison, G.C., 1986: Prediction of streptococcal pharyngitis: an option for school nurses?. In this article the authors address the dilemma confronting school nurses in determining whether or not to counsel parents about seeking medical care for a child with a sore throat. The use of a clinical scorecard in the school setting as an aid i...

Owonikoko, T.; Loberg, C.; Gabbert, H.E.; Sarbia, M., 2001: Comparative analysis of basaloid and typical squamous cell carcinoma of the oesophagus: a molecular biological and immunohistochemical study. Twenty-three cases of basaloid squamous cell carcinoma (BSCC) and 23 stage-matched pairs of typical squamous cell carcinoma (SCC) of the oesophagus were investigated for molecular aberrations. Polymerase chain reaction (PCR) was used to detect los...

Lavdas, E.; Tsougos, I.; Arikidis, N.; Roka, V.; Fezoulidis, I.V.; Vlychou, M., 2014: Evaluation of fat saturation and contrast enhancement on T1-weighted FLAIR sequence of the spine at 3.0 T. To evaluate T1-weighted fast spin echo (FSE) and fast T1-weighted fluid-attenuated inversion recovery (FLAIR) imaging, pre and post contrast administration, and assess the necessity of fat saturation regarding normal anatomical structures, degener...

Shimi, A.; Keyhani, M.; Bolurchi, M., 1976: Salmonellosis in apparently healthy dogs. When rectal swabs were examined from 672 dogs in Tehran, Iran, 52 (7.7 per cent) yielded Salmonellae of 20 different serotypes. The 672 dogs examined comprised 472 household pets, 181 kennel dogs and 19 strays. They showed an incidence of 4.4, 15....